In shaving, it is desirable to achieve a close shave, while also providing good shaving comfort. Factors that affect shaving performance include the frictional resistance between the blade edge and the skin, the cutter force applied by the blade to the hair.
It is common for razor blades used for wet shaving to include a thin polymer coating on the blade edge, which can reduce the frictional resistance between the blade edge and the skin and thereby reduce the cutter force of the blade, greatly improving shaving comfort. Such coatings are described, for example, in U.S. Pat. No. 5,263,256 to Trankiem, the entire disclosure of which is incorporated by reference herein. The polymer coating also helps the blade glide smoothly along the surface of the skin, potentially managing the skin bulge as the razor is pulled along the user's skin.